Light Staying On: the Door Switch on a 700

Why it matters

Sub-Zero treats light as heat. The 700 guide says a door or drawer left ajar has its lights disabled to keep excess heat out. A lamp that stays lit behind a shut door does the opposite, and a bulb burning round the clock reaches the end of its life sooner.

Nobody sees inside a closed door, so this fault shows sideways: bulbs failing early, a warm top shelf, a glow at the edge of a door that is not quite home.

The order of work

The door first. An out-of-level cabinet, a sagging hinge, a rubbing panel or a bin in the way can hold a door short of the point where it registers as shut. With the alarm on, a door the 700 reads as open chimes after 30 seconds: the owner’s first clue.

Then the switch. If the door closes fully and the light still burns, the part that senses the door, or its wiring, is next.

Then the control. Only when the door and the switch prove sound do we look at the control.

What the guide leaves to the owner

Bulbs. Sub-Zero lets an owner replace them with the unit switched off at its control panel and gloves on. The opposite fault has an owner step too: when lights are out after a door stood ajar, the guide’s step is to keep that door closed for an hour. Lights still dark after that go to service.